New Study Reveals Genetic Marker for Tourette Syndrome

The search for a genetic marker for Tourette Syndrome (TS) is starting to bear fruit, according to a report from the Tourette Syndrome Association's International Consortium for TS Genetics presented at the 3rd International Scientific Symposium on TS, held over the weekend in New York.

David Pauls, a Yale Child Study Center (New Haven, CT) population geneticist, said that the consortium's study discovered "two small regions of the genome that may be strongly implicated with TS and four additional regions that may contribute to the baffling disorder."

"This is the best information that we've ever had in terms of the actual location of a gene or genes for TS," Pauls said. "It is a major step forward."

The geneticist noted that evidence accrued over the last 30 years suggested that genetic factors are important for the expression of TS, and that it is highly probable that several genes are involved. "This new data uncovered by our ten-center International Consortium strengthens that hypothesis and provides pointers to where these genes may be," he said.

The multi-site study, accepted for publication in the American Journal of Human Genetics, involved 76 families with two or more children affected with TS, a total of 110 sibling pairs in all. Researchers collected clinical information as well as blood samples for DNA analysis. A panel of markers relatively evenly spaced across the genome were typed in all the families to see whether there was an excess sharing of particular forms of markers by the affected sibling pairs. A change in a particular region in TS-affected siblings provides evidence that that region might be close to an abnormal gene. Each of the markers has many different forms; an increased sharing of these different forms suggests increased susceptibility for TS.

"The next step," said Pauls, "is to get more data from more families to see whether these findings hold up. In the process, our group will try to narrow the length of the region so that it is small enough to discover which gene is increasing the susceptibility for Tourette Syndrome."

Sponsored by the TSA, consortium members include more than 30 investigators working in five countries.

The 3rd International Scientific Symposium on TS convenes every ten years, bringing together distinguished scientists from around the world sharing major findings and cutting-edge developments in all facets of TS and associated disorders. It is sponsored by the Tourette Syndrome Association with support from the National Institutes of Health.

TS is a much misunderstood neurological disorder that affects untold thousands of Americans. The most common symptoms are involuntary motor and vocal tics, including throat clearing, noises, sniffing, and tongue clicking. Common motor tics include rapid eye blinking, head jerking, shoulder shrugging, and facial grimacing. There is no cure, but medications can reduce the severity of symptoms for some.

Established in 1972, the Tourette Syndrome Association Inc. is a nonprofit voluntary national organization that works to educate the public and physicians about the disorder. The association also funds scientific research to find a cure for TS, and provides support to people with TS and their families.

For more information: David L. Pauls, Professor of Child Study Center and Psychology, Yale University, New Haven, CT 06520. Tel: 203-785-5345. Email: david.pauls@yale.edu.